Static and Seismic Responses of Eco-Friendly Buried Concrete Pipes with Various Dosages of Fly Ash

Sayedali Mostofizadeh,Kong Fah Tee

doi:10.3390/app112411700

Abstract

In this paper, an evaluation based on the detailed failure has been conducted for underground sewage Geopolymer concrete (GPC) pipes under static and seismic loadings with consideration of the optimal time steps in the time-dependent process related to nonlinear behavior of GPC pipes in static and dynamic analyses. The ANSYS platform is employed for improving an advanced FE model for a GPC pipe which can simulate the performance of underground GPC pipes containing various percentages of fly ash (FA) as a Portland cement (PC) replacement. Subsequently, the time-dependent model is used to assess the efficacy of this concrete admixture (FA) in the structural response of the unreinforced GPC pipe in FEM. Indeed, the generated GPC pipe with the three-dimensional model has the potential to capture the nonlinear behavior of concrete which depicts the patterns of tensile cracking and compressive crushing that occur over the applied static loads in the FE model. The main issue in this paper is the assessment of the GPC pipe response typically based on the displacement due to static and seismic loadings. The numerical results demonstrated that the optimal displacement was obtained when the structural response had typically the lowest value for GPC pipes containing 10–30% FA and 20% FA under static and seismic loadings, respectively. Indeed, a reduction by 25% for the vertical displacement of a GPC pipe containing 20% FA was observed compared to that without FA under time-history analysis.

Highlights

The issue of an appropriate collapse probability along with the optimal response of underground concrete pipes has been highlighted in numerous investigations
The numerical results demonstrated that the optimal displacement was obtained when the structural response had typically the lowest value for Geopolymer concrete (GPC) pipes containing 10–30% fly ash (FA) and 20% FA under static and seismic loadings, respectively
The elements with the mesh sizes of 1, 075, 0.5, and 0.25 m are used for FE analysis of the model including two soil types and the GPC pipe with a length of 7.6 m; It is observed that the numerical results of 0.5 m and 0.25 m are obtained without significant variations compared to those of 1 m and 0.75 m

Summary

Introduction

The issue of an appropriate collapse probability along with the optimal response of underground concrete pipes has been highlighted in numerous investigations. Numerous investigations on the performance and design of underground pipes have been carried out using either static or dynamic loads without any precise vindication related to the section of loading type [8,9,10]. Chaallal et al [11] investigated the behavior of underground flexible pipes under static loading. Rakitin and Xu [12], MacDougall et al [13], and Lay and Brachman [14] explored the behavior and the design of underground concrete pipes under static surface loads. McGrath et al [15]

Objectives

Findings

Discussion

Conclusion